A supranational union is a type of international organization that is empowered to directly exercise some of the powers and functions otherwise reserved to states. A supranational organization involves a greater transfer of or limitation of state sovereignty than other kinds of international organizations.

The European Union (EU) has been described as a paradigmatic case of a supranational organization, as it has deep political, economic and social integration, which includes a common market, joint border control, a supreme court, and regular popular elections.

Another method of decision-making in international organisations is intergovernmentalism in which state governments play a more prominent role.